Carburetor heater



June 9, 1925. 1,541,583

c. c. MERz CAEBURETOR HEATER Filed Aug'. 28. 1922 2 sheets-sheet 1 c. c. MERZ cARBURToR HEATER F'il'ed Aug. 28 1922 2 Sheets-Sheet 2 Patented June 9, 1925.

UNITED STATES CHARLES C. MERZ, F INDIANAPOLIS, INDIANA.

CARBURETOR HEATER.

Application led August 28, 1922. Serial No.' 584,615. l

T 0 all whom it may concern Be it known that I, CHARLES C. MERZ, a citizen of the United States, and a resident of the city of Indianapolis, in the county of v Marion and State of Indiana,.havelinvented certain new and useful Improvements in a Carburetor Heater;` and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had l0 to the accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

This invention relates to carburetor heaters, and particularly vto a device for introducing heated gases into a fuel mixture priorl v vtical section showing details of the check to the introduction of said fuel mixture into the combustion chambers of an internal combustion engine. v

In the use of the relatively low grade fuels which are now generally supplied, the

application of heat is necessary under certain conditions for efficient operation,

under other conditions, particularly when operating at high speeds, the heating of the fuel mixture causes a loss of eiiiciency. It is therefore desirable that heating means be provided which are automatically regulable toheat the fuel mixture only at -such times as the heat is required for proper and eicient operation.

It is an object of the present invention to provide a carburetor heater which is controlled by velocity and pressure conditions existing within the carburetor Iand Within the intake and exhaust manifolds.

It is also an object of this invention to provide means for adding heated gases to fuel mixture for internal combustion engines to bring about more satisfactory operation 49 at low speeds without affecting the efficiency of high speed operation.

It 1s another object of this invention to rovide means for introducing exhaust gases 1nto the fuel mixture prior to the .introduction thereof into the combustion chambers of the engine, said means being adapted to automatically cease functioning in high` engine speeds.

It is an important object of the present 50 invention to provide a fuel mixture heating means, which is automatically regulable and which may be economically manufactured and conveniently installed. l

Other and further important objects of the present'invelltion will be apparent from the while disclosures in the specication'- and the acl:

companying drawings.

The invention shown on the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a side elevation with parts in section showing an installation embodying the principles of this invention.

F1 re 2 is a view similar to Figure 1 showing a slightly modified formv of installation.

Fi re 3 is a view similar to Figure 2 `showing another form of installation,

Figure 4 is an enlarged longitudinal vervalve in the types of installations shown in Figures 2 and 3.

Fio'ure 5 is an enlarged detail section showing the discharge end of the conduit in the type of installation shown in Figure 1.

As shown on the drawings:

The reference numeral 1 indicates a. usual exhaust manifold, which is adaptedVv to discharge exhaust gases at 2 into a usual exhaust pipe. Mounted adjacent' said exhaust manifold 1 is an intake manifold 3 which hasconnected thereto a carburetor i, and which acts to discharge fuel mixture from said carburetor 4 into the combustion chambers of an internal combustion engine on which said manifolds are mounted. In the form of this invention disclosed in Figure l, a conduit 5 connects in the exhaust manifold 1 at a point adjacent to discharge end 2 thereof, and said conduit 5 extends to the carburetor 4 and is connected to said carburetor at a point 6 leading into the mixing chamber of said carburetor. The inner end of said conduit 5 inside the mixing chamber of the carburetor is formed downwardly as indicated at 7, said downwardly formed portion opening in an upstream direction relative to the flow of fuel mixture through the carburetor and being flared outwardly to form a bell-shaped openingas indicated by the reference numeral 8. The

(in a preferred form) is I provision of the connection afforded by the4 j cient to overcome the ofie t gas pressure existi manifold l. l`l"he v i mixture through the corresponds to the amoiuu o opening of a usual :ottle valve l), and as the opening S is located on the supply side of said valve it is apparent that when said throttle valve 9 is in closed or nearly cle l position corresponding to low engine eds, there will be little velocity ellect er ted on the discharge end of the conduit o, and conscquently there will he large introduction of exhaust gases and a cor. quent desirable heating of the fuel mixture at low engine speed. it open positions oi' the throttle il and high engine speeds, however, the velocity effect of the fuel mixture flowing through the carburetor will be surlicient to balance the pressure of the exhaust gases, and there will be no introduction of exhaust gases or application of heat to the fuel mixture, which isof course a desirable condition for high Speed operation. The provision of the flaring opening 8 on the downwardly formed portion 7 enhances the action of the fuel mixture in equalizing the pressure ofthe exhaust gases and is desirable in many installations, although it is apparent that this flaring opening may be omitted under certain conditions.

In the embodiment of thisV invention disclosed in Figure S2, conduit l() is connected in the exhaust manifold 1 through a boss 11, and said conduit 10 extends into the exhaust manifold for a considerable distance, being preferably positioned horizontally as indicated in the drawings. Said conduit 10 extends to and is connected in the earburetor mixing chamber through a restricted opening l2 at a point adjacent the edge of the throttle 9 when the same is in idling or substantially closed position. On account of the high degree of sub-atniospheric pressure existing at the restricted opening 12 when the throttle isin closed or nearly closed position, correspi *ding-to low engine speeds, there will be at this time a consideralole introduction of heated exhaust gases into the fuel mixture, due to the difference in pressure between the interior of 'the exhaust manifold and the mixing chamber of the carburetor under sucli condition. At open throttle positions and high engine speeds, the sub-atmospheric pressure at the restricted opening 12, of course, greatly diaf the exhaust the exhaust ow of the fuel L of course cor f minishes approaching a condition of atmos.

pheric pressure, and in view of the fact that the conduit 10 in the exhaust manifold opens downstream relative to the How of the exhaust eases, there is, of course, a reducm tion of pressure at said open end which tends to assist in the equalizing or balancing effect, and there is thus brought about a suihcient equalization to cut oft the flow of exhaust gas into the fuel mixture at such open throttle positions and correspondingv high engine speeds. The introduction oil any fuel mixture from the carburetor into the exhaust manifold is prevented by the provision of a check valve 13, which is mounted in a casing la connected in the conduit 10, said check valve 123 preferably being constructed of a' square piece of metal or similar material. having a rounded end adapted to seat by gravity in an aperture 15 formed in a transverse partition 16 iu the casing 14. The squared portion of said check valve 13 is freely movable in a cylindrical recess in a casing 1T threaded in the upper side of the casing 1d. By making the check valve 13 square and movabljyY mounting the same in a cylindrical recess, there is little danger of failure of operation due to clogging which might be brought about by carbon in the exhaust gas,

In the embodiment of this invention disclosed in Figure 3, the conduit 10 is positioned in the exhaust manifold in the same manner as in the 'installation disclosed in Figure Q, with the exception that in this construction a Venturi tube may, if desired, be mounted'in the exhaust manifold surrounding the open 'end of the conduit 10 in such a manner as to effect an increased r'eduction in pressure adjacent the open end of said conduit. The other end of the conduit 10, instead of being connected into the carburetor at a point adjacent the throttle valve 9, is connected into the intake manifold through a restricted opening` 19 a short distance above the point at which the carburetor is connected to said intake manifold. In this installation the check valve 13 should be made somewhat heavier than the check valve in the installation shown in Figure 2, in order that it may only be operated by the suction in the intake manifold and so that there may be no openingT thereof due to the exhaust pressure in itself.

lt will be apparent from the foregoing that this invention provides a means for heating the inflowing fuel mixture prior to the introduction thereof into the combustion chambers of the engine, and also pro vides means whereby the supply of heat is reduced at increased engine speeds and entirely stopped at high engine speeds. As previously explained, the factors of velocity and 'pressure both within the exhaust man! ifold and within the fuel inlet connections determine the amount of heated gas introduced into the fuel mixture. The apparatus embodying this invention may be economically manufactured and conveniently installed, and there is little likelihood of the same getting out of order after installation.

l am aware that numerous details of construction may be varied through a wide range without departing from the prinri/insee ciples of this invention, and "I therefore do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art. i v

I claiml as my invention:

, l. In an internal combustion engine, fuel mixture inlet'means, a throttle valve therefor, exhaust gas outlet means, a conduit connecting said means, and an elbow extension on said conduit having; la flaring opening into said fuel mixture inlet means on the supply side of said throttle valve.

2. In an internal combustion engine, fuel mixture inlet means, a throttle valve there for, exhaust gasoutlet means, a conduit conn-eting said means, and an extension on said conduit having a flaring openinggextending into the fuel mixture inlet means in an upstream relation to the How of fuel mixture therethrough and en the supply eide of said throttle velu 3. In anv internal combustion engine7 fuel lieixture inlet means, exhaust gas outlet ineens, a conduit connecting said means und extending into the exhaust gas outlet means and opening in the direction of the flow through said exhaust gas outlet means, and a, venturi disposed around' thefopen end of said conduit.

In testimony whereof I have hereunto subscribed my 'name in the presence of two subscribing witnesses.

' CHARLES C. MERZ. Witnesses:

CARLION HILL, HARRY K. GRUBB. 

